MODELING OF TUNNELLING IN STRATIFIED INHOMOGENEOUS SOIL MASS

Abstract

The tunnelling, through rock/soil media, causes change in state of surrounding soil/rock media, which may disturb the stability of tunnel and structures at ground surface. The extent of effect, due to tunnelling, on soil/rock media, surrounding the tunnel, is governed by many factors like Geological conditions, Method used for tunnelling, the way of tunnelling and others. The geological conditions such aS soil properties (cohesive strength, internal friction angle, permeability etc.), position of underground water table, past stress history of media, stratification of media etc. play a leading role as an influencing factor compared to others. In the present thesis, numerical analysis, based on finite element method, is done for analyzing the effect of different geological conditions. The software package PLAXIS V8 is used for numerical analysis. The soil profile in Munich, Germany, is considered as input model for numerical analysis. The results obtained by numerical analysis give an idea, in first sight, for deciding the most critical geological condition, which may be proof as a worst condition during tunnelling and will play a deciding role in designing of tunnel support.